how many hearts does a butterfly have

Butterflies, like other insects, do not have a heart in the sense of a single muscular pump like humans. They do have a long, chambered dorsal vessel that functions as the circulatory system, pumping hemolymph (insect “blood”) through their body. The dorsal vessel runs along the top side of the abdomen and consists of a series of chambers that help move hemolymph around to bathe the organs. So, there is one main dorsal vessel acting somewhat like a heart, not multiple hearts.